2017-09-12 22:22:03

by Vladis Dronov

Subject: [PATCH] nl80211: check for the required netlink attributes presence

nl80211_set_rekey_data() does not check if the required attributes
NL80211_REKEY_DATA_{REPLAY_CTR,KEK,KCK} are present when processing
NL80211_CMD_SET_REKEY_OFFLOAD request. This request can be issued by
users with CAP_NET_ADMIN privilege and may result in NULL dereference
and a system crash. Add a check for the required attributes presence.
This patch is based on the patch by bo Zhang.

This fixes CVE-2017-12153.

References: https://bugzilla.redhat.com/show_bug.cgi?id=1491046
Fixes: e5497d766ad ("cfg80211/nl80211: support GTK rekey offload")
Cc: <[email protected]> # v3.1-rc1
Reported-by: bo Zhang <[email protected]>
Signed-off-by: Vladis Dronov <[email protected]>
---
net/wireless/nl80211.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 0df8023..fbd5593 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -10903,6 +10903,9 @@ static int nl80211_set_rekey_data(struct sk_buff *skb, struct genl_info *info)
if (err)
return err;

+ if (!tb[NL80211_REKEY_DATA_REPLAY_CTR] || !tb[NL80211_REKEY_DATA_KEK] ||
+ !tb[NL80211_REKEY_DATA_KCK])
+ return -EINVAL;
if (nla_len(tb[NL80211_REKEY_DATA_REPLAY_CTR]) != NL80211_REPLAY_CTR_LEN)
return -ERANGE;
if (nla_len(tb[NL80211_REKEY_DATA_KEK]) != NL80211_KEK_LEN)
--
2.9.5

2017-09-15 07:18:08

by Johannes Berg

Subject: Re: [PATCH] nl80211: check for the required netlink attributes presence

On Wed, 2017-09-13 at 00:21 +0200, Vladis Dronov wrote:
> nl80211_set_rekey_data() does not check if the required attributes
> NL80211_REKEY_DATA_{REPLAY_CTR,KEK,KCK} are present when processing
> NL80211_CMD_SET_REKEY_OFFLOAD request. This request can be issued by
> users with CAP_NET_ADMIN privilege and may result in NULL dereference
> and a system crash. Add a check for the required attributes presence.
> This patch is based on the patch by bo Zhang.

Huh. Applied, thanks.

johannes